Generally, a hydraulic shock absorber is composed of a piston which partitions the inside of a cylinder into an extension side oil room and a compression side oil room, an orifice for connecting the extension side oil room and the compression side oil room, a piston rod which extends from the cylinder interlocking with the piston, and an accumulator which allows entrance and exit of a hydraulic operating fluid equivalent to the volume of an entered portion of the piston rod in the cylinder.